Method for swaging needle-arms and fulcrum-bars



F. H. DOERR. METHOD FOR SWAGING NEEDLE ARMS AND FULCRUM BARS.

APPLICATION FILED OCT- 29, 1919.

Patented Oct. 25, 1921.

Z/Jii'saea:

, UNITED STATE;

PATENT. OFF Iced FRED" H: 130mm, enchant; narxnsavncniean, ssienoaroonnnni TALKING.-

- MAQHINECOMPANY,OF.QHICAGO,; .ILLI1\TOIS,. AQCORPORATION-"OE iLLINorss ErHonfroR sW G NG NEEDLELABMS' AND rULoRUM-BARs;

To all witom it concern/'3 zen of the United States; residingat Grand Rapids, inthe county of Kent and Stateof Michigan, have invented; certain new" and useful Improvements in Methods for Swaging Needle-Arms and Eulcrum-Bars, of"

which-the following is a specification.

My invention relates to the manufacture of needle arms for use with sound box diaphragms of sound reproducing machines, and has to do especially with the formation of an integral needle arm and fulcrum bar formed by swaging from cold metal.

My invention contemplates the formation of a needle arm and fulcrum bar from a single plate of metal of the desired thickness by swaging and forming while themetal is in the cold state, from the initial operation of blanking to the final operation of a completed integral needle arm andfulcrum bar.

Qne of the objects of my invention is the formation by swaging of a needle arm and fulcrum bar.

1 Another object is to form an integral needle arm and fulcrum bar for sound box diaphragms of sound reproducing machines.

A further object is to provide a means of making needle arms and fulcrum bars which is inexpensive and expeditious, and to improve such bars for successful commercial use.

On the accompanying sheet of drawings I have shown a series of views of the various steps which may be employed in subjecting a cold piece of metal to swaging to form the bar embodying my invention.

Figures 1 and 2 show in plan and side elevation a blank formed from cold metal' of suitable thickness and shape and size.

Figs. 3 and 4 show the effect of the first forming operation wherein it will be noted that the part which is to serve as the needle arm proper has been bent at right angles to the fulcrum bar and also that the needle arm portion has been curved.

Figs. 5 and 6 show the efi'eot of the first swaging operation, which is to straighten the curve formed in the arm of Figs. 3 and 4, so that no cracks or imperfections of any sort will be developed at the length between the needle and fulcrum arm portions.

Figs. 7 and 8 show the needle arm portion flattened so that the form of arm shown S peeification of Letters Patent. P t te o t; 2'5

Application-filed"October29, 1919. Serial No. 334,254.

d 1 in FigsIQ and 10 -may beblanked' from the Beit-known that I, FREnH. Donnma c1t1- flattened arm portion:

formed with the '=usual' goose-neck and" provided with a bead for attachmentto the dia= phragmpin'" the usual manner. i

In carryin out my invention, metal of suitable quallty and thickness is subjected to a blanking operation wherein the blank shown in Figs. 1 and 2 is formed, the parts of the blank being the needle arm part 15 and the fulcrum bar portion 16. The blank is then subjected to a forming operation wherein the part 15 is bent at right angles to the part 16, and in order to prevent breakage near the bead a curve 17 is made at the fulcrum arm portion. The part 15 is then subjected to a swaging operation wherein it is straightened as shown in Fig. 6. Then the arm portion 15 is subjected to a second swaging operation wherein itis flattened as shown in Figs. 7 and 8, the plane of the swaging operation being in a direction of 90 to that necessary to form the parts as shown in Figs. 3 and 4. The flattened portion 15 is then subjected to a forming operation wherein the finished part 15 with the member 18 as shown in Figs. 9 and 10 is turned out, the member 18 being utilized to provide a means for connectingthe arm to the diaphragm of the sound box. The final operation which may be a forming operation includes twisting of the member 19 through an angle of 90 so that the arm will lie in the plane of the diaphragm to which it is to be fastened and then forming the goose-neck whereby the distance between the fulcrum bar 16 and the point of attachment 20 between the member 18 and the diaphragm (not shown) may be adjusted. If desired, the upper end of the portion 15 may be heated to bend the same through 90. However, this heating is not a necessary requisite as the bend may be accomplished while the metal is cold. It will be noted that by my invention it is possible to produce a combined needle arm and fulcrum bar from cold metal, which makes posisble a reduction of time necessary to produce needle arms and fulcrum bars, increasing the production thereof, decreasing the cost and turning out such articles of uniform quality and in great quantities.

While I have described more or less precisely the details of construction of my in vention, yet I do not wish to be understood as limiting myselfthereto, as I contemplate changes in form and the proportion of parts and the substitution of equivalents as circumstances may suggest or render expedien't, Without departing from the spirit of my invention. I

I claim:

;1; The method of making integral needle arms and fulcrum bars which consists in forming a blank having a narrow arm forming portion and a transverse fulcrum forming portion, then developing the relative relation of arm and fulcrum bar by bending, followed by swaging, then flattening the arm, then trimming said blank-away to the the arm to the ultimate required shape and size, and then bending arrangement of form and parts desired.

2. The method of making needlearms integral with fulcrum barswhich consists in first punching a 'blank'shaped somewhat like a cross from a metal sheet of suitable thickness, then swaging said blank to turn up the upright with respect to said cross plece, then flattening the upright by swaging same, then blanking the flattened upright ,to theshape and size desired,'then finally, bending and twisting the upper end ofthe uprightgto provide aportion for-attachment to. a diaphragm. V Signed at Grand Rapids, Mich, this 7th day of October,.1919. H c a p 1 FREDDOERR. 

